Figure 4-15.Buck-arm construction.
Figure 4-16.Side-arm construction.
Figure 4-17.Standard flat-strap crossarm brace.
Buck arms are used at comers and at points when
branch circuits are taken off at right angles to the main
line (fig. 4-15).
Side arms are used in alleys or other locations when
it is necessary to clear buildings. (See fig. 4-16.)
Braces are used to give strength and rigidity to the
crossarm. Metal crossarm braces are made of either flat
bar or light angle iron.
The size used varies with the
size of the arm and the weight of the conductors. The
usual flat-strap brace for ordinary distribution work
(fig. 4-17) is 38 inches long and 1/4 by 1 1/4 inches. One
end is attached to the crossarm by means of a carriage
bolt and the other to the pole by means of a lag screw.
Figure 4-18.A V-shaped angle-iron crossarm brace.
Figure 4-19.Crossarm brace installation.